1. Field of the Invention
The invention relates to tools for installing blind anchor nuts, and, more particularly, to manually operable tools for installing blind anchor nuts.
2. Description of the Prior Art
In U.S. Pat. No. 3,587,271 to Rigot, there is described a tool for installing blind anchor nuts. In that patent, "blind anchor nuts" are defined by a device comprising a tubular body portion and an internally threaded nut portion, the nut portion being capable of being pulled towards the tubular body portion to deform the body portion to tightly grip the walls of a suitable aperture in which the body portion is inserted, thereby to install the anchor nut securely in the aperture. The anchor nut is "blind" in that its installation requires access to one side only of the aperture. One example of such a blind anchor nut is that widely sold under the Registered Trade Mark "NUTSERT."
Such tool requires different sized components for the particular blind anchor nuts to be installed. For example, in the Rigot patent, an annular anvil 13 is described containing therein a mandrel 17 for engaging the anchor nut to be installed. Such anvil 13 and mandrel 17 is adapted to be changed when desired so that the threaded portion 18 of mandrel 17 can theadably engage the anchor nut. Thus, when used with anchor nuts of differing internal thread diameters, members 13 and 17 must be changed. In the Rigot patent, this is accomplished by a small retaining screw 26 which engages anvil 13. By loosening screw 26, anvil 13 can be removed and both mandrel 17 and anvil 13 replaced by a mandrel 17 and anvil 13 of the proper dimensions.
In addition, when replacing mandrel 17, the key 24 of Rigot must also be replaced. In Rigot, this is accomplished by another small set screw 31 engaging key 24. In both cases, it takes time to find the proper tool to loosen the screws 26 and 31. Such screws may be allen screws thus requiring a particular type of tool to loosen the same, such as an allen wrench. Since such screws by their very nature are extremely small, there is a strong possibility of losing the same making further use of the tool impossible until a replacement is found.
In addition to being time-consuming, the torque encountered in using the Rigot tool could break off the small screws 26, 31 requiring such screws to be drilled out or otherwise removed before the tool could be used again.
It is thus necessary to have a manually operable tool for installing blind anchor nuts which does not require any external tools to change the components thereof necessary to installing anchor nuts of different sizes.